vlog95: for a part/pv look for the strength at the driver

A part/pv passes strength information so we need to use the real driver to get the appropriate drive information.
steveicarus · Feb 13, 2013 · 8b4dc05 · 8b4dc05
1 parent 6de80ad
commit 8b4dc05
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Showing 2 changed files with 45 additions and 3 deletions.
diff --git a/tgt-vlog95/expr.c b/tgt-vlog95/expr.c
@@ -190,7 +190,6 @@ static void emit_expr_binary(ivl_scope_t scope, ivl_expr_t expr, unsigned wid)
 	    emit_expr(scope, ivl_expr_oper2(expr), wid);
 	    fprintf(vlog_out, "))");
 	    break;
-	    break;
 	default:
 	    emit_expr(scope, ivl_expr_oper1(expr), wid);
 	    fprintf(vlog_out, "<unknown>");

diff --git a/tgt-vlog95/logic_lpm.c b/tgt-vlog95/logic_lpm.c
@@ -108,10 +108,53 @@ static void emit_gate_strength(ivl_net_logic_t nlogic, unsigned strength_type)
                     "gate", ivl_logic_file(nlogic), ivl_logic_lineno(nlogic));
 }
 
+/*
+ * Look for a single driver behind an LPM that passes strength information
+ * and get the real drive information from it.
+ */
+static void get_unique_lpm_drive(ivl_lpm_t lpm, ivl_drive_t *drive1,
+                                 ivl_drive_t *drive0)
+{
+      ivl_nexus_t nex = ivl_lpm_data(lpm, 0);
+      unsigned idx, count = ivl_nexus_ptrs(nex);
+      unsigned have_driver = 0;
+
+      for (idx = 0; idx < count; idx += 1) {
+	    ivl_nexus_ptr_t nex_ptr = ivl_nexus_ptr(nex, idx);
+	    ivl_drive_t cur_drive1 = ivl_nexus_ptr_drive1(nex_ptr);
+	    ivl_drive_t cur_drive0 = ivl_nexus_ptr_drive0(nex_ptr);
+	    if ((cur_drive1 == IVL_DR_HiZ) &&
+	        (cur_drive0 == IVL_DR_HiZ)) continue;
+	    assert(! have_driver);
+	    *drive1 = cur_drive1;
+	    *drive0 = cur_drive0;
+	    have_driver = 1;
+      }
+
+	/* This should never happen. */
+      if (! have_driver) {
+	    fprintf(stderr, "%s:%u: vlog95 error: Unable to find drive "
+	                    "information for strength transparent LPM.\n",
+	                    ivl_lpm_file(lpm), ivl_lpm_lineno(lpm));
+	    vlog_errors += 1;
+      }
+}
+
 static void emit_lpm_strength(ivl_lpm_t lpm)
 {
-      emit_strength(ivl_lpm_drive1(lpm), ivl_lpm_drive0(lpm), 2,
-                    "LPM", ivl_lpm_file(lpm), ivl_lpm_lineno(lpm));
+      ivl_lpm_type_t type = ivl_lpm_type(lpm);
+      ivl_drive_t drive1 = IVL_DR_STRONG;
+      ivl_drive_t drive0 = IVL_DR_STRONG;
+	/* This LPM object passes strength information so we need to look
+	 * for the strength information at the real driver. */
+      if (type == IVL_LPM_PART_PV) {
+	    get_unique_lpm_drive(lpm, &drive1, &drive0);
+      } else {
+	    drive1 = ivl_lpm_drive1(lpm);
+	    drive0 = ivl_lpm_drive0(lpm);
+      }
+      emit_strength(drive1, drive0, 2, "LPM",
+                    ivl_lpm_file(lpm), ivl_lpm_lineno(lpm));
 }
 
 static void emit_delay(ivl_scope_t scope, ivl_expr_t rise, ivl_expr_t fall,